Telephone plug



July 10, 1928.

M. ALDEN TELEPHONE PLUG Filed OCT.. l2, 1925 3010101010107/ SalI-lm Y Y1 l anwm INVENTOR, Mlion alzen,

A TTORNE Y.

Patented July 10, 1928.

UNITED STATES PATENT OFFICE.

MILTON ALDEN, F SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO ALBEN MANUFAC-TUBING CO., OF SPRINGFIELD, MASSACHUSETTS, .L CGRFORATION OF MASSACHU-SETTS.

TELEPHONE PLUG.

Application led October 12d; 1923. Serial No. 668,126.

This invention relates to improvements in terminals for telephone plugssometimes known as a tip ack77 for making electrical contacts forclosing telephone circuits. 1t

is particularly designed for use in connection with radio or wirelessapparatus where it is often desirable to change the electricalconnections.

Broadly, it comprises a threaded tubular member with means for securingit to the casing of the apparatus or box on which it is to be used andlocated within and secured to the tubular member is a second tubularmember having one end split or slotted and spaced from the interior ofthe threaded tubular member to provide an elastic end, and7 a springencircling the split portion ot' the tube, whereby when a plug isinserted the spring will yield to provide suliicient friction forholding the plug in place in the split tubular member. This is desirableas oftentimes the diameters of the plugs are uneven or vary in size.

Referring to the drawings:

Fig. 1 is a sectional view showing a portion of the casing with acylindrical member threaded into the same andthe tubular member with aslitted end having a spring encircling the split portion.

Fig. 2 is an elevational view of the threaded cylindrical member removedfrom the casing or box.

Fig. 3 is a detail view of the tubular split member, and

Fig. 4 is a detail view of the spring which encircles the split portionof the tubular member.

Referring tothe drawings in detail:

1 designates a portion of the casing ot a vradio or electricalapparatus, 2 the exteriorly threaded cylindrical member which isthreaded into an opening oi' the casing, the 'threads being indicated at3. el. is an integral shoulder portion preferably formed with flat sidesor surfaces to receive a wrench or other tool for threading the member 2into the casing. Formed in the member 2 is a longitudinal opening 5which opening 5 communicates with the enlarged opening (i. 7 is atubular member which is located within the openings 5 and 6 of themember 2 as shown in Fig. 1. This member is formed with a reducedportion 8 that is located. in

the enlarged opening G of the member 1.

The reduced portion is formed with two slits 9 for providing theflexible terminal or end portions 1() or 11. Encircling the portions 10and 11 is the coiled spring 1Q. This spring is :tor the purpose ofnormally drawing the parts 10 and 11 toward each other for exerting a.pinching eilect on the plug when it is inserted. 13 is the plug which isattached to the telephone cable 14. This cable is formed with the usualcore 15 that is secured to the plug 13 by means of the solder 16. lV henthe plug 13 is inserted between the ilexible or elastic portions 10 and11 it will make a good electrical contact therewith. The springs 12permit the parts 10 and 11 to yield outwardly. This construction permitsthe plug 13 to malte a good electrical contact with the tubular member't' even iii' the diameter of the plug varies. As shown in the drawingsthe dimensions are greatly enlarged. In practice they are madeconsiderably smaller. The larger portion of `the tubular member issecured in the opening 5 by a driving tit, or it may be soldered inplace. TheA externally threaded tubular member 2 is secured in place bymeans of the nut 17. 18 designates an electrical wire, and 19 a nut forsecuring the wire rigidly in place on the member 2 and against the nut17.-

The present improvement is one that can be manufactured very cheaply andin large quantities. The tubular member is readily slotted and itsnormal diameter reduced at one end; the larger' or inner end of thismember can be driven into the externally threaded cylindrical member 2for producing a good driving tit, the coiled spring 12 is then slippedinto the enlarged annular recess 6 which exerts sufficient constrietingforce to normally move the slitted end inward against the pin 13. Theexternally threaded member 2 is then assembled in the casing 1 as shown.The thread of the member 2 is easily produced in quantities on a screwmachine and the recess G formed. It will therefore be seen that l haveproduced a telephone plug or tip jack that-can be readily and cheaplyconstructed and installed. In case any of the parts shouldy becomeweakenedbr broken they can be quickly replaced by new parts.

I desire to he understood. that I do not limit myselilA to the exactconstructionfdisclosed but equivalenfJ structures are included.

What I claim is:

In combination, a one piece member having an external thread for a partof its length which thread terminates in a shoulder part at one end andsaid member having an internal opening with an Unthreaded surface ofdifferent diameters extending throughout the length of the member, atubular member having a smooth outer surface secured in the smaller partof the unixhreaded opening, which tubular member is formed with aslitted portion for providing resilient parallel finger ends and acoiled spring in the larger part of the Unthreaded opening of theexternally threaded member for engaging and normally forcing the saidends towards each other, wherebyy when a plug having a long cylindricalsuriare iS inserted in the tubular member between the said ends thelat/ler will yield outwardly against the action of said spring means.

MILTON ALDEN.

